Slot machines are well known gaming devices. In the past they have been embodied as first mechanical and later electromechanical devices having three or more reels. Each reel includes about its periphery a plurality of symbols (and blanks). When play is initiated as by inserting a wager and pulling a handle, the reels are spun eventually slowing to present symbols or blanks at a payline. If the combination of symbols is one of a predetermined schedule of winning outcomes, the player receives a reward. If the outcome is a losing outcome, the player loses their wager.
Recently it has been known to provide video displays controlled by a processor which simulates spinning reels and the presentation of winning or losing outcomes. Furthermore it has been known to provide these devices with bonus sequences which are triggered by the player obtaining certain outcomes during play of the primary game. One such game is a game wherein five reels are displayed. The player makes a wager to enable from one to five or more paylines. When play is prompted, the processor simulates the spinning of the reels and the eventual presentation of outcomes for each enabled payline. If the player has a winning outcome on any enabled payline they receive a reward. If the player receives a bonus enabling outcome, the display switches to a bonus display. In one machine the display is of a barnyard where the player is requested to select one of five displayed pigs. Upon making the selection, the display displays a farmer washing the mud off of the pig to reveal a bonus. In another game five fishermen are shown and the player is prompted to select one. The display shows the selected fisherman reeling in a fish to display the bonus.
These bonus game have gained popularity in casinos.
In another type of game, when the player obtains a predetermined outcome during play of the game, a sequence is initiated wherein a wild symbol marches through the display creating different combinations and different payouts. One such game is as described in Australian Patent AU-B43613/97 published Feb. 5, 1998 by Bennett and titled "Slot Machine With Roaming Wild Symbol".
Bonus games are, as stated above, popular among players. However, one drawback is that, in one type of machine, the player only gets to select symbols as a means for randomly selecting a bonus. The player, by obtaining a bonus enabling outcome knows they are going to obtain a bonus, he just does not know how much. There is no means by which the player might expect to increase his bonus during play or presentation of the bonus sequence. With roaming wild symbols, the prize of the feature depends on combinations created by the roaming wild symbol while moving from position to position.
In Hooker, U.S. Pat. No. 4,184,683, a slot machine is set forth where the player can hold a reel for the next spin of the remaining reels in an effort to obtain a winning outcome on a payline. This game does not relate to bonuses in relation to the play of a primary game.
There is a need for a slot machine game and method which overcomes the drawbacks noted above, which provides for a bonus sequence and which provides the player during the bonus sequence with a chance to increase the bonus to be awarded.